Mobile communications systems continue to be developed to provide wireless communications services to a greater variety of electronic devices. In more recent years, third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architectures have been developed to support more sophisticated communications services to personal computing and communications devices than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user may enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy third and fourth generation networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to increase rapidly.
More recently it has been recognised that rather than providing high data rate communications services to certain types of electronics devices, it is also desirable to provide communications services to electronics devices that are simpler and less sophisticated. For example, so-called machine type communication (MTC) applications may be semi-autonomous or autonomous wireless communication devices which may communicate small amounts of data on a relatively infrequent basis. Some examples include so-called smart meters which, for example, are located in a customer's house and periodically transmit information back to a central MTC server data relating to the customer's consumption of a utility such as gas, water, electricity and so on.
Whilst it can be convenient for a communications device such as an MTC type device to take advantage of the wide coverage area provided by a third or fourth generation mobile telecommunication network there are at present disadvantages. Unlike a conventional third or fourth generation communications device such as a smartphone, a lower complexity device may operate with a lower bandwidth and be preferably relatively simple and inexpensive. The type of functions performed by the MTC-type device (e.g. collecting and reporting back data) do not require particularly complex processing to perform.
As will be appreciated, there may be a desire for many types of communications devices and mobile communications networks to use communications resources as efficiently as possible and to reduce power consumption. It is known for example to reduce the power consumed by a communications device by performing what is known as discontinuous reception. Discontinuous reception is a technique in which a communications device may be radio resource connected, but after monitoring a control channel to determine whether communications resources have been allocated to the communications device, the communications device can sleep for a remainder of a time before another transmission may occur on the control channel. A communications device may also be configured with a short and a long discontinuous reception timer. If no activity is detected for a short discontinuous reception time, then the communications device moves to a long discontinuous reception timer. Accordingly the communications device can save power.